Index: Lib/test/test_file.py
===================================================================
--- Lib/test/test_file.py	(revision 77873)
+++ Lib/test/test_file.py	(working copy)
@@ -134,6 +134,41 @@
     def testReadWhenWriting(self):
         self.assertRaises(IOError, self.f.read)
 
+    def test_issue_5677(self):
+        # Remarks: Do not perform more than one test per open file, since that
+        # does NOT catch the readline error on Windows. Do not use self.open,
+        # since this does NOT catch the readline error on OpenSolaris.
+        self.f = open(TESTFN, "w")
+        self.f.write(u"xxx")
+        self.assertRaises(IOError, self.f.read)
+        self.f.close()
+
+        self.f = open(TESTFN, "w")
+        self.f.write(u"xxx")
+        self.assertRaises(IOError, self.f.readline)
+        self.f.close()
+
+        self.f = open(TESTFN, "w")
+        self.f.write(u"xxx")
+        self.assertRaises(IOError, self.f.readlines)
+        self.f.close()
+
+        self.f = open(TESTFN, "wb")
+        self.f.write(b"xxx")
+        self.assertRaises(IOError, self.f.read)
+        self.f.close()
+
+        self.f = open(TESTFN, "wb")
+        self.f.write(b"xxx")
+        self.assertRaises(IOError, self.f.readline)
+        self.f.close()
+
+        self.f = open(TESTFN, "wb")
+        self.f.write(b"xxx")
+        self.assertRaises(IOError, self.f.readlines)
+        self.f.close()
+
+
 class CAutoFileTests(AutoFileTests):
     open = io.open